This invention is concerned with applying longitudinal stripes to pencils, particularly pencils of hexagonal cross-section.
Existing techniques for applying longitudinal paint stripes to the sides of pencils have several disadvantages. Striping by hand is time consuming, expensive and poorly adapted to mass production. Automated devices are complex, waste paint, and require frequent maintanence. For example, in devices of the type disclosed in German Pat. No. 710,069 (1941) and in Czechoslovakian Pat. No. 68,585 (1941) open-sided receptacles containing paint are provided, and the pencil is drawn along the open sides of the receptacles in contact with a pool of paint. Seals are required at the ends of the receptacle to prevent rapid loss of paint. In the well-known squeegee device, as disclosed in U.S. Pat. No. 2,331,983 to Kaiser, for example, paint is applied to all sides of the pencil and is wiped off of certain sides by wipers. The seals and wipers must be replaced as they wear. Disassembly and cleaning of the devices is not an easy matter.
In the wire manufacturing art various techniques are employed for applying stripes to insulated conductors. U.S. Pat. No. 2,880,698 to Olson discloses a striping device employing a passage having long channels of U-shaped cross-section that are filled with paint or other coating material from a suitable supply. The applicator is formed in two parts that are spring biased toward each other about a pivot and that mate to define the passage. U.S. Pat. No. 2,610,607 to Isenberg discloses a rotary striper in which reservoirs containing the striping material have spring biased followers to force the coating material through orifices in the wall of a bushing which is rotated about an insulated conductor. Such striping devices are not sufficiently simple, economical, precise and reliable for mass production striping of pencils.